Growing chillies from seed (looking back at 2021)

In this article you will learn all about growing chillies from seed, using both store bought chilli peppers as well as seeds bought from a reputable local supplier.

Previously we have always grown chillies and peppers from small plants bought at the garden centre. We have tried several different chilli varieties ranging from mild pepper plants to the hotter varieties.

But there is no reason to spend money on small plants when seeds are much less expensive and easy to germinate and grow into tall, beautiful chilli plants. As long as you follow a few simple rules to maximize your chances of getting the healthiest chilli and pepper plants possible.

Here’s what you need to know about how to grow chilli and pepper plants from seed and looking after your plants during the different stages of growth – all the way to harvest time.

How to grow chillies from seeds

You do not have to be a skilled or experienced gardener to grow chili peppers from seed.  

But to grow chillies from seed does require time, planning, patience and attention to detail. Chillies grow slow and plants take a long time to develop. This is where planning comes into the picture. You need to start early in the season when most people are yet to think about gardening.

And when I say early I mean early as in planting your seeds indoors in January or February.

8 steps from seed to chilli plant

1. Plant chilli seeds in starter pots indoors in January/February
2. Use a lean potting soil and a pot with good drainage
3. Place pot in a warm (20-25 Celsius /68-77 Fahrenheit) and light location
4. Provide extra artificial light using grow lights for best result
5. Replant into a larger pot or plastic container gradually. 
6. Place pot in a light but a bit cooler location (18 C/65 F ) when the plant is established.
7. Consider moving the pot outdoors when the lowest temperature is above 10 C (50 F)
8. Water regularly and add nutrition every 4-6 weeks

Plant chilli seeds in starter pots in January/February

Chili plants take time to grow and develop. And to grow plants and give them the best possible chance to develop and bear fruit, we plant our seeds indoors early in the year.

You can of course grow chillies indoors all year-round as long as you have extra lighting.
Planting chilli seeds harvested from store bought chillies and peppers
Using plastic starter pots and peat pellets to plant chilli seeds

Make sure you choose a pot with good drainage. If you are planting many seeds you can buy seed starter trays or why not use a biodegradable cardboard egg carton?

All you are looking for is an environment where the chilli seed can germinate and sprout those first leaves.

Your chilli plants will grow stronger in a smaller pot. The root system of the chilli plant will grow until it hits an obstacle.

When the roots hit a stop they will divide, branch out and continue to grow. And this is exactly what you want. A healthy and compact root system.

Fill your pot with unfertilized potting soil and water thoroughly. Let any excess water run off to leave you with a moist, but not wet, soil.

Seeds do not need fertilized soil to germinate. Quite the opposite actually. If you use a fertilized soil the fragile new roots may burn, leaving you with an empty pot. The seed itself contains all the energy the plant needs to germinate and sprout its first leaves. 

Now plant 1 or 2 seeds per starter pot. Plant the seeds about 1cm (½ inch) deep and cover with soil.

To keep the soil moist and warm you should cover the pots with a plastic film when the seeds are planted. Make sure you make holes in the plastic to allow air to circulate.

If you can see condensation forming on the plastic film you need to increase air circulation.

Place your pot in a warm location with good ventilation and plenty of light. Avoid direct sunlight. An even temperature around 20-25 degrees Celsius (68-77 degrees F) is ideal for the seeds to develop into strong and compact seedlings.

Living in zone 7 we do not have enough natural light in January. Adding a grow light helps the seedling develop. From February onwards the natural light is usually sufficient for the seedlings to develop.

Using plastic film to cover the pot will help keep the soil moist. You should not let the soil dry out. Water the pot using a spray bottle or bottom water in a a water bath if needed.

Harvesting chilli seeds from store bought chillies
I also harvested seeds for planting from store bought chillies and peppers

The seeds that were harvested from store bought chillies were removed by hand and planted in clearly labelled pots.

How to care for the young chilli seedlings

After about 10-14 days the chilli seeds germinate and sprout first leaves. These first leaves store and supply the young seedling with energy to grow while the root system and true leaves are forming.

Chilli seeds germinating and sprouting first leaves
Chilli seeds sprouting first leaves

When the first leaves are replaced with true leaves it is time to transplant your chilli seedling into a larger pot.

Again, remember that the chilli plant prefers a smaller sized pot to allow the root system to grow strong. Choose a slightly bigger pot measuring 7-8 cm (3 inches). 

At this stage you should use normal fertile soil to fill up the new larger sized pot. But be gentle and let any soil that sticks to the root system carry over to your new pot. 

When you transplant your chilli pepper seedlings you can plant them slightly deeper than before. This will help the plant to develop a strong and healthy root system. The soil line should be just below the first pair of true leaves. 

Caring for the young established chilli plant

As the young chilli plant gets established you should, if possible, move it to a slightly cooler growing environment (20-22 degrees Celsius/ 68-72 Fahrenheit). 

Healthy chilli seedling almost ready for new larger pot
Seedling almost ready for larger pot

The cooler growing environment will help develop a compact plant with a robust and strong root system. If the growing environment is too hot you will end up with a tall and leggy plant. 

But do not put the plant in a shady location, you want the plant to have access to plenty of light.

As the plant grows you will need to gradually increase the size of the pot. But it is important to increase the size gradually.

Why?

Roots of the chilli plant will grow until they hit a stop. When they hit a stop the roots branch out and continue to grow in new directions.

But if you place a young chilli seedling or plant in a 30 liter (8 gallon) container the roots will grow long and spindly. 

This is not what you want. You want a compact and strong root system.

By gradually increasing the size of the pot the root system will be forced to branch out several times creating a compact, robust and strong root system.

Be prepared to replant your chilli plants 4-6 times before placing them in their final growing place.

Water your chilli plants regularly

Chillies need to be watered regularly and during the height of summer this could mean morning and evening. If possible, do not shock the plant with cold water. Room temperature water is much preferred by the chilli plants.

But do keep in mind that no plants like being waterlogged. Keep the soil moist but not soaking. You do not want the soil to dry out. 

I use grow bags for larger plants like chillies (and tomatoes). The grow bags are made from material that breathes to help control moisture. I find this helpful compared to plastic pots where I have to rely on the drain holes to get rid of excess water.

Terra cotta pots are of course a great solution if you are prepared to spend the money. 

Since we always have many plants on the go I find it more economical to make and use grow bags.

I make the grow bags from landscape fabrics. You can follow my guide to make your own grow bags

When to start adding fertilizer

When you plant your seeds you never add fertilizer. The seed itself contains all the energy and nutrients that is needed for successful germination. 

But when the young chilli plants start to get established you should start adding fertilizer to help the plant develop. 

Liquid fertilizer crash course

The fertilizers you buy have a three digit combination written on the label. These numbers indicate the level of Nitrogen, Phosphorus and Potassium for that particular brand. 

A 10-10-10 fertilizer is considered an all-purpose fertilizer. The 10-10-10 combination indicates that there is 10% of each of Nitrogen, Phosphorus and Potassium in the fertilizer. 

But your fertilizer will also include other ingredients such as for example calcium. These other ingredients will be listed on the bottle. With chillies you also want your fertilizer to include Calcium.

As I see it you have 3 options (or variations thereof):

1. Expensive: You can buy 1 specific fertilizer to address the specific needs of every single plant you grow. 

2. Budget: Buy a 10-10-10 all purpose fertilizer as it does include all the most important nutrients.

3. Functional: Focus on buying a couple of fertilizers that meet the needs of your plants during the different main stages of growth. This is what I do and I have 2 bottles – see below.

Chilli plants Two main stages of growth

I use the same liquid fertilizers that I use for my tomatoes. And it has been successful. 

I always use liquid fertilizers as they give the plant a quick boost compared to the slow-release pellets you can also buy. 

Healthy plant with chillies and peppers
Healthy chilli plant with peppers

Follow the instructions on the bottle but it is better to with a low to moderate amount of fertilizer and increase to listed dosage after 1 or 2 applications. You do not want to risk overfertilizing your chilli plants and it is always difficult to know how fertile the soil is.

You can of course choose to use the same type of fertilizer throughout the growing season.

As I have already stated I use two different fertilizers for optimal growth.

During the initial stages of growth you want the established chilli plant to grow strong leaves. And to give the plant what it needs you need a fertilizer with a high ratio of nitrogen. I use a fertilizer with the ratio 10-3-5. 

As you can see it is still 10% nitrogen. Same as for the all purpose fertilizer with 10-10-10. You have to think about the ratios in relative terms. The 10-3-5 combination holds a higher relative concentration of nitrogen as it contains less Phosphorus and Potassium. 

When the plant has grown strong and starts to set flowers you should switch to a fertilizer with less nitrogen. At this stage more new foliage means less fruit. And you want to help the plant develop fruit rather than more green leaves and foliage. I use a fertilizer with the ratio 10-3-5 better suited to help fruit production.

Plant Chillies in grow bags (or pots)

I keep my chillies in grow bags for the entire growing season.

Planting chillies in grow bags or pots makes it easy to move the plants if, for example, weather conditions change for the worse.

When you choose your pot or container it is important to

  • Choose a pot, grow bag or container with good drainage
  • Gradually transplant chilli plant into larger pots

For most single chilli plants is a 20 litre (5 gallon) size pot with a depth of about 30 cm (12 inches) about right.

If you live in a cooler climate you can go smaller, whereas warmer climates will require a larger size container.

You can move your chilli plants outdoors when the temperature holds above 10 degrees Celsius (50 degrees Fahrenheit) for the entire day and night. 

You should always harden your plants for a week or so to gradually introduce them to their new growing environment.

Avoid direct sun during the hottest part of the day and find a warm spot shielded from the wind.

Harvest chillies

Late summer or maybe early fall it is finally time to harvest your chillies.

To pick your chillies you simply grab them and gently push up against the branch where they are connected. 

Chilli peppers ready for harvest
Chilli pepper harvest time

The pepper will snap off and now you can choose to dry them, make chilli sauce or simply use them in your cooking. Or why not freeze chillies for later use in cooking.

You can also cut them in two halves lengthwise to extract the seeds. Leave the seeds to dry and grind them down to make your own chilli powder. This can be a real eye opener if you are growing hot chillies.

Be warned – some chillies are extremely hot. So choose your chilli varieties carefully.

You can of course also dry and grind the actual chilli fruits to make chilli flakes. Or instead of drying on the window sill you can oven dry the fruits on low heat with the over door open. Then let the chillies cool down before you grind them into flakes.

Or make your very own chilli sauce. It is very easy and you just need basic ingredients like chillies, garlic, apple cider vinegar, brown sugar and water. Finish off by adding salt and pepper to taste.

Please feel free to reach out if you want my favorite recipe.

Pests, problems and diseases

Regular manual inspection of you plants is key whether you grow from seeds or buy established plants from local garden centres.

And I do recommend you apply the sound principles of companion planting for peppers to give your plants the best possible growing environment. I invite you to read out beginners guide that explains why companion planting makes sense and how to apply it to any garden including yours.

Or why not grow garlic indoors in water or pots as a companion plant for your pepper seedlings and plants. Read all about it in the article: "Tips to grow garlic indoors faster – in water or soil"
The tell tale sign of leaf miner attach on leaves
The tell tale sign of white squiggly lines from leaf miners

Keep an eye on your plants and inspect leaves, flowers and branches for pests and disease. Look for anomalies. Are there leaves, branches or flowers that look different?

As you get used to inspecting your plants a quick daily scan and a more thorough weekly inspection will be enough to catch attacks early. And early detection is important.

The more common pets and diseases include aphids, leaf miners and thrips.

Most of the pests will feed on the leaves and it is relatively easy to spot their work. 

If you have a young plant that is infested you should immediately remove the plant from other plants you grow in your garden. Yes, this is another advantage when you grow chillies in pots or grow bags – the plants become mobile.

If the infestation is small start by removing leaves and pests by hand where possible. Next treat the plant with Neem oil. Spray the plant with the Neem oil water solution in the evening and then again the following morning.

You can also buy commercial insecticides and pesticides but I have no experience of using them. Ask for advice at your local garden shop.

The good news is that and established chilli plant can survive pests and diseases if caught and treated early.

Should I pinch chilli plants for stronger plants?

You may have read that you should pinch your chilli plants to help the plant grow more bushy.

And this is true for chilli plants that are meant to grow bushy. But keep in mind that there are several varieties of chilli plants that grow tall. And you do not want to pinch these plants before they reach maturity.

Read the seed package to make sure what kind of plant you are growing before you pinch your chilli plants.

If it is a bushy chilli variety you can pinch the top when the plant reaches 15 cm (6 inches).

If you are unsure what variety you are growing it is better to leave the plant alone.

Should I soak chilli seeds before planting?

You do not have to pre-soak to germinate chilli seeds. Your seeds will however germinate faster if you soak them in room temperature water the night before planting. 

But your seeds will germinate even if you do not soak them before planting.

And as your chilli plant will need a long time to grow and produce fruits I do not see this step as necessary when you germinate chilli seeds.

What I learnt from growing chillies from seed

Starter pot overcrowded with seedlings
One of many overcrowded starter pots.

I read a lot of gardening books and also speak with fellow gardening professionals. 

And I went into this little project thinking I had it all figured out. Looking back it went well but there were a few surprises along the way.

To summarize I started with more than 100 seedlings grown from seeds. Most seeds germinated successfully.

  • During the early stages of growth I thinned out well over half the seedlings. 
  • Some of these seedlings were simply weaker where more than one seed germinated successfully. Other seedlings had to be thinned out as I had planted too many seeds in one and the same starter pot.
  • 25 seedlings (young plants) were transplanted into grow bags (you can also use individual pots).
  • 3 plants were lost. Two plants were “burnt” on one and the same day when placed next to a glass window in my greenhouse on a surprisingly hot midsummer day. One plant I think I over-fertilized even though I followed the instructions carefully.
  • I ended up harvesting chillies from 22 of the plants in total. But the way I look at it I only lost 3 plants.

A few tips (9) that I learned from sowing seeds this year

  1. Warm sunny growing conditions are good but extreme heat can kill your plants. And even too warm (25+ C/ 77+ F) can be bad as it will give you long, leggy plants.
  2. Chilli seedlings need a lot more light than I thought. Or else seedlings grow leggy. 
  3. Chilli plants do not like direct sunlight during the hotter part of the day.
  4. Do not start with large containers too early. It is important to gradually increase pot size – roots need to hit a stop to branch out and develop compact strong root systems.
  5. Do not pinch or top all types of chillies – not all chillies are meant to grow bushy.
  6. Do start really early – sow seeds January/February early.
  7. Sow seeds sparingly. 1 or 2 seeds per starter pot. Or else you will just thin them out later.
  8. Adding a low dosage of fertilizer works better than a high dosage once or twice per season.
  9. Use seeds from a reputable supplier. It is fun to use seeds harvested from store-bought peppers and chillies but there is no real advantage.

Meet the author: Mattias is an experienced gardener spending most of his free time on his knees among herbs, plants and garden vegetables. For the past two years he has been sharing gardening projects and how-to tutorials on the NordicLavender website and YouTube channel.